1. Field of the Invention
This invention relation relates to plugs, and more particularly, to polymeric plugs that are useful for plugging flexible polymeric pipe and tubing, particularly polymeric pipe and tubing comprising crosslinked polyethylene (“PEX”), during hydrostatic pressure testing.
2. Description of Related Art
Building codes typically require hydrostatic pressure testing of water supply lines during installation. With the widespread use of polymeric pipe and tubing for water supply lines in recent years, devices and methods previously used for plugging metal or other rigid plastic conduits for hydrostatic testing during rough-in have been adapted to some extent for use with polymeric tubing. The devices and methods currently available typically require the use of a torch, crimping tool or glue to plug a tube. For example, brass plugs that have been used in the past to plug polymeric tubing during hydrostatic testing are relatively expensive to manufacture and require additional labor and the use of tools to crimp them into place. Some prior art devices have a sleeve that slides onto the end of a pipe or tubing before a plug is inserted into the open end, after which the sleeve is crimped over the inserted plug. More recently, hydrostatic test plugs have been disclosed that are made of plastic, but have a configuration that is similar to the metal plugs. Other prior art devices used in hydrostatic testing of pressurized water systems are disclosed, for example, in U.S. Pat. Nos. 7,232,159 and 7,272,971.
Notwithstanding the products that are previously known or commercially available, a need exists for hydrostatic test plugs that can be easily and inexpensively installed in polymeric tubing without using tools, that will provide a reliable hydraulic seal during pressure testing, and that are easily removable following testing by cutting off the pipe section containing the plug.